Three guys from suburban Johnson County grow up within blocks of one another, independently pursue show business careers and almost simultaneously become successful comedy icons in TV, film and live performance.

Now Rob Riggle, Jason Sudeikis and Paul Rudd are coming home to use their cultural clout for charity.

On Saturday, the trio will be back in their old stomping grounds to preside over the Big Slick Celebrity Poker Tournament at Harrah’s North Kansas City Casino.

The event is expected to raise as much as $50,000 for Children’s Mercy Hospital and to generate no shortage of yuks for those who pony up to compete or who attend a post-play gathering in the casino’s Voodoo Lounge.

There is no big secret to their involvement, the three claim. They’re Kansas Citians. This is what Midwesterners do.

“I love being from KC,” Riggle said. “I wear my Chiefs hat all over LA. I like being from the Midwest. Midwesterners are polite, well-mannered, good people. I’m really proud of my roots.”

Sudeikis — who has been known to wear a Jayhawks cap or a RecordBar T-shirt during “Saturday Night Live” broadcasts — said no one should be surprised that humor blooms in the heartland. After all, the Midwest produced Johnny Carson and David Letterman.

“Look at Chicago. The Second City has always been a great hub for comedy. The Belushis, the Farleys,” Sudeikis said. “Lots of great comedians come out of Canada, and isn’t Canada basically the Midwest, only colder?”

‘You from KC?’

Sudeikis has been a regular on “SNL” since 2005, and has a recurring role on “30 Rock.” Riggle also has logged time on “SNL” as well as Comedy Central’s “The Daily Show” and several films, including last summer’s hit comedy, “The Hangover.” Rudd has worked in film since 1992, appearing in productions from “Romeo + Juliet” to “The 40-Year-Old Virgin.”

The three didn’t know each other back in the day, though Rudd said his parents, both in the travel business, often spoke of a colleague named Kathy Sudeikis whose son turned out to be … well, you get it.

“I knew Rob at KU and I knew Jason before he was on ‘SNL,’” Rudd said.

All three attended Shawnee Mission West High School. Sudeikis had heard of Rudd from his speech and debate teacher there.

“I didn’t meet him until much later,” Sudeikis said. “Rob and I met in 2003 when we both were auditioning for ‘SNL.’ I was talking to some people about home and Rob came over and says, ‘You from KC?’

“I said, ‘93rd and Lamar.’

“He said, ‘98th and Lowell.’

“Friends ever since.”

Rudd and Sudeikis say the idea to have all three participate in the poker tournament was Riggle’s.

“The three of us were talking last year, and Rob he said he was thinking about doing this charity tournament and that maybe we should all do it,” Rudd said. “It took Jason and me about a second to go, ‘Oh, absolutely.’ But Rob has been the engine behind it.”

Trained as a classical actor, Rudd said he was a bit self-conscious about his comedy chops, especially compared with those of his colleagues, who have logged years of stand-up and improv experience.

“I learned to act in a place where you don’t change a word of the script,” he said. “You don’t mess with Shakespeare. I never did stand-up or sketch comedy.

“But beginning with ‘Anchorman,’ I found myself on movie sets where people were encouraged to wing it. You look at the script but you also make it up as you go along. If you think of something funny, you throw it in there.”

Turned out that Rudd was very good at improvisational goofing. The DVD of his comedy hit “I Love You, Man” features extensive outtakes of Rudd giving different readings of the same lines — some of the stuff funnier than what ended up in the movie.

Comedy and the Corps

Of the three men, Riggle may have the most curious story. When he is not making people laugh he wears the uniform of a lieutenant colonel in the Marine Corps Reserve.

“I joined the Marines when I was 19 at KU,” Riggle said. “I had a dream that I’d be the next Top Gun. But I was also a theater and film major, which was sort of an unusual pairing.”

Riggle received flight training, but before completing it he realized that he was going to have to make a choice — become a full-time pilot or heed the call of show business.

“I realized that once I put those wings on they’d have me for the next eight years,” Riggle said. “I quit flying for the Marines, went to ground duty and then when I’d fulfilled my contract I went up to New York and started acting.”

But he didn’t quit the Corps. As a reservist, he has served in Afghanistan, Kosovo and Liberia, as well as with the Corps’ New York City Public Affairs unit. He doesn’t give rah-rah speeches about military service, but it is pretty clear it is a treasured part of his life.

“It’s nice for me to wear both hats,” he said. “Everybody is capable of doing more than one thing.”

This weekend will be particularly busy for Riggle. He has a new movie opening. In “Killers,” he co-stars with Ashton Kutcher and Katherine Heigl in an action comedy about a hit man whose past encroaches on his new life as a married suburbanite.

On Friday, Riggle will throw out the opening pitch for the Royals at Kauffman Stadium. (Informed of this, Sudeikis wondered aloud, “Really? Can you throw a ball that far underhand?”)

Riggle, Rudd and Sudeikis won’t be the only celebs participating in the tournament. They have rounded up several showbiz acquaintances who will be on hand. The guest list is top secret, but Rudd’s mother, Gloria Rudd, has seen it and says there are some very big names on it.

Going for the gigs

Being successful in comedy is a never-ending job, Riggle said.

“There’s no finish line in this business. You go from one job to the next and if you’re lucky you get some good gigs. Maybe a job that lasts for several years. That’s a lifetime in show biz.”

The hardest part of the job is rejection, Riggle said.

“I’ve been told ‘no’ a thousand times. It’s painful and you have to have a pretty thick skin because it’s all so subjective. ‘Why didn’t I get the job?’ ‘I don’t like your eyebrows. Or your hair.’ Regardless of how funny or talented you are, it’s humbling.

“You have to really, really want a career in show business. If it were easy anybody could do it.”